A method for modeling and decoupling longitudinal register error of a roll-to-roll printing system under skip-color working condition, a roll-to-roll printing machine and a computer program product

Abstract

This invention discloses a method for modeling and decoupling control of longitudinal registration error in roll-to-roll printing systems under color-skipping conditions, a roll-to-roll printing press, and a computer program product. The method includes: establishing a registration error model based on variable mesh length according to the roll material transport characteristics and printing unit dynamic parameters under color-skipping conditions in a roll-to-roll printing press; analyzing the change in effective printing length between adjacent printing units caused by selective shutdown, and deriving the registration error models for the first printing unit and subsequent units after color skipping; integrating the coupling relationship between tension fluctuation, angular velocity adjustment, and mesh elastic deformation into the registration error model to construct a registration error model for the complete system under color-skipping conditions; constructing a selective decoupling compensator based on Lyapunov stability theory to compensate for coupling disturbances caused by color skipping; and achieving roll-to-roll color-skipping printing registration accuracy control through the selective decoupling compensator combined with pre-color-skipping registration control. This invention significantly improves the registration accuracy of roll-to-roll multi-color printing.

Description

Technical Field

[0001] This invention belongs to the field of precision printing technology, and particularly relates to a method for modeling and decoupling control of longitudinal registration error in roll-to-roll printing systems under color skipping conditions, a roll-to-roll printing machine, and a computer program product. Background Technology

[0002] Roll-to-roll (R2R) printing is a highly efficient and continuous flexible material processing technology that plays a crucial role in the manufacturing of microelectronics, new energy, and multifunctional composite materials. This technology sequentially transfers multi-color or multi-layer patterns onto a moving flexible substrate using multiple printing units connected in series. Its core challenge lies in maintaining extremely high registration accuracy. Registration error, the deviation between the actual printed pattern and the ideal position, is a key factor affecting product functionality and yield. Especially in fields such as precision electronic circuits, micron-level sensors, and multi-layer optical films, even minute registration errors can lead to a significant decrease in product performance or even complete failure.

[0003] Existing research has made significant progress in registration control, primarily focusing on tension stabilization strategies and error decoupling methods. In tension control, various methods have been developed, including indirect tension observers, distributed partitioned control architectures, dynamic tension compensation strategies, and multimodal adaptive algorithms, effectively suppressing system tension fluctuations and improving operational stability and anti-interference capabilities. Regarding registration control, research has proposed multiple strategies, including feedforward PD control, model-based full decoupling methods, data-driven learning control, and predictive control frameworks, significantly improving the performance of traditional control structures under complex coupling conditions and providing multiple feasible paths for achieving high-precision registration. However, these methods are all based on the assumption that all printing units are in operation, failing to consider the special operating condition of "color skipping"—that is, selective shutdown of some printing units—common in actual production. Color skipping alters the coupling relationship between units, causing the system's dynamic characteristics to differ significantly from the normal operating mode.

[0004] Therefore, there is an urgent need to propose a method for modeling and decoupling control of longitudinal registration error in roll-to-roll printing systems under color skipping conditions, as well as a roll-to-roll printing machine and computer program product. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a method for modeling and decoupling control of longitudinal registration error in roll-to-roll printing systems under color skipping conditions, a roll-to-roll printing machine, and a computer program product, which significantly improves the registration accuracy of roll-to-roll multicolor printing and increases production efficiency.

[0006] To achieve the above objectives, this invention provides a method for modeling and decoupling control of longitudinal registration error in a roll-to-roll printing system under color skipping conditions, comprising:

[0007] Based on the roll material transport characteristics and printing unit dynamic parameters under the color skipping condition of roll-to-roll printing press, a registration error model based on variable mesh length is established.

[0008] The changes in effective printing length between adjacent printing units caused by selective disabling are analyzed, and the registration error model of the first printing unit and subsequent units after color skipping is derived.

[0009] The coupling relationship between tension fluctuation, angular velocity adjustment and elastic deformation of the mesh is incorporated into the registration error model to construct a registration error model for the complete system under the color-changing condition.

[0010] A selective decoupling compensator is constructed based on the registration error model of the complete system and combined with Lyapunov stability theory to compensate for the coupling disturbance caused by color jumping.

[0011] The selective decoupling compensator, combined with pre-color-skipping registration control, enables roll-to-roll color-skipping printing registration accuracy control.

[0012] Optionally, establishing a registration error model based on variable mesh length includes:

[0013] In the case of color skipping, the longitudinal registration error is defined as the positional deviation between the printed mark of the current printing unit and the printed mark of the previous printing unit.

[0014] Based on the registration error model under normal working conditions, it is divided into three parts: upstream unit of the color-jumping unit, color-jumping unit, and downstream unit of the color-jumping unit, and modeled separately. For the upstream unit of the color-jumping unit, the registration error model is the same as the model when no color-jumping occurs; for the color-jumping unit, there is no registration error; for the downstream unit of the color-jumping unit, a corresponding registration error model is constructed.

[0015] Optionally, analyzing the changes in effective print length between adjacent print units caused by selective deactivation includes:

[0016] After determining the position of the color-jumping unit, the registration error of the first printing unit downstream of the color-jumping unit becomes the deviation of the marked position between this unit and the unit preceding the color-jumping unit;

[0017] The mesh length between the color-blocking unit and the downstream unit is merged into a new length;

[0018] The mesh tension between the first printing unit downstream of the color-blocking unit and the unit preceding the color-blocking unit is redefined;

[0019] Based on the variation in mesh length, the downstream unit alignment error model is derived segment by segment.

[0020] Optionally, incorporating the coupling relationship between tension fluctuations, angular velocity adjustments, and elastic deformation of the mesh into the registration error model includes:

[0021] The segmented equations for the registration error under the color-changing condition are combined and organized.

[0022] The relationship between registration error and mesh tension in the frequency domain is obtained through Laplace transform;

[0023] Construct the registration error-registration control model expression for the complete system under the color-changing condition;

[0024] Clarify the coupling relationship between the registration error and the registration control of the current and upstream units.

[0025] Optionally, a selective decoupling compensator can be constructed based on the registration error model of the complete system combined with Lyapunov stability theory, including:

[0026] Based on the registration error model of color-changing working conditions, the compensation conditions for system stability are derived.

[0027] The stability and convergence of the system were analyzed using the Lyapunov energy function.

[0028] Construct a feedforward compensation mechanism to ensure that the coupling effect of upstream unit angular velocity adjustment on downstream unit is zero;

[0029] The frequency domain expression of the compensation amount is derived to achieve deterministic disturbance cancellation.

[0030] Optionally, controlling roll-to-roll color-skipping printing registration accuracy by combining the selective decoupling compensator with pre-color-skipping registration control includes:

[0031] The upstream alignment control quantity is divided into the upstream alignment control output of the current unit and the decoupling compensation quantity for the upstream alignment control.

[0032] The decoupling method for units before color transition continues the normal model;

[0033] After color-changing, the decoupling compensation formula of the unit is redesigned based on the new model;

[0034] Upstream registration control is used to reduce uncoupled registration errors, while selective decoupling compensation is used to counteract the effects of upstream coupling.

[0035] To achieve the above objectives, the present invention also provides a roll-to-roll printing machine, comprising:

[0036] Unwinding section, rewinding section, feeding section, unloading section, and multi-color printing section.

[0037] The unwinding section releases the roll material, and the tension control system maintains the stability of the roll material tension.

[0038] After being pulled and tensioned by the feeding section, the roll material smoothly enters the multi-color printing section;

[0039] After entering the multi-color printing section, the roll material is pressed against the roller under the action of the pressure roller to transfer the pattern, and the patterns are stacked one after another to form multi-color printing;

[0040] The discharge section performs post-processing and pre-rewinding preparations, including final drying of the ink, material cooling to stabilize the ink layer, and finally stabilizing the conveying tension.

[0041] The take-up section rewinds the finished product into a roll, ensuring that the roll is tight, neat, and free of internal wrinkles or indentations, thus completing the roll winding process.

[0042] Each section is connected by a constant roll tension as the main line. The feed section and the output section serve as tension buffer hubs to absorb fluctuations and ensure that the roll material enters and leaves the multi-color printing section smoothly. All printing rollers are controlled by a synchronous drive system to ensure consistent linear speed. The registration error system reads the printing marks and links each printing unit to ensure registration accuracy. The entire process is coordinated by a central controller to achieve efficient collaboration among all modules.

[0043] To achieve the above objectives, the present invention also provides a computer program product, comprising: a computer program used to implement the longitudinal registration error modeling and decoupling control method of the roll-to-roll printing system under color skipping conditions.

[0044] Technical effects of this invention: This invention discloses a method for modeling and decoupling control of longitudinal registration error in roll-to-roll printing systems under color-skipping conditions, a roll-to-roll printing machine, and a computer program product. Based on the roll material transmission characteristics and printing unit dynamic parameters under color-skipping conditions in roll-to-roll printing machines, a registration error transmission model based on variable mesh length is established. By analyzing the changes in effective printing length between adjacent units caused by selective discontinuation of printing units, the registration error equations for the first printing unit and subsequent units after color skipping are derived. The coupling relationship between tension fluctuation, angular velocity adjustment, and mesh elastic deformation is integrated into the model to construct a registration error model expression for the complete system under color-skipping conditions. Based on Lyapunov stability theory, a selective decoupling compensator is designed to compensate for the coupling disturbances caused by color skipping, significantly improving the registration accuracy of roll-to-roll multi-color printing and increasing production efficiency. Attached Figure Description

[0045] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0046] Figure 1 This is a flowchart illustrating a method for modeling and decoupling control of longitudinal registration error in a roll-to-roll printing system under color skipping conditions, according to an embodiment of the present invention.

[0047] Figure 2This is a flowchart illustrating the decoupling control method according to an embodiment of the present invention;

[0048] Figure 3 This is a schematic diagram of a typical roll-to-roll printing press according to an embodiment of the present invention;

[0049] Figure 4 This is a simplified structural diagram of a selective deactivation unit according to an embodiment of the present invention;

[0050] Figure 5 This is a schematic diagram of the initial input of the second unit for verifying the longitudinal registration error model under a color-blocking condition according to an embodiment of the present invention.

[0051] Figure 6 This is a schematic diagram of the longitudinal registration error verification model of units 2 and 3 under the color-blocking condition according to an embodiment of the present invention;

[0052] Figure 7 This is a schematic diagram of the longitudinal registration error in units 5, 6, and 7 under a color-blocking condition according to an embodiment of the present invention.

[0053] Figure 8 This is a schematic diagram of the registration error of units 2 and 3 under a model-based selective decoupling control method according to an embodiment of the present invention;

[0054] Figure 9 This is a schematic diagram of the registration error of units 5, 6, and 7 under a model-based selective decoupling control method according to an embodiment of the present invention. Detailed Implementation

[0055] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0056] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0057] like Figure 1 As shown, this embodiment provides a method for modeling and decoupling control of longitudinal registration error in a roll-to-roll printing system under color skipping conditions, including:

[0058] Step S100: Based on the roll material transport characteristics and printing unit dynamic parameters under the color skipping condition of roll-to-roll printing press, establish a registration error transmission model based on variable mesh length;

[0059] Step S200: Analyze the change in effective printing length between adjacent units caused by selective disabling, and derive the registration error equation for subsequent units;

[0060] Step S300: Integrate the coupling relationship between tension fluctuation, angular velocity adjustment and mesh tension into the registration error to construct a registration error model of the complete system under the color-changing condition;

[0061] Step S400: Design a selective decoupling compensator based on Lyapunov stability theory to achieve precise cancellation of upstream control coupling.

[0062] Furthermore, step S100 specifically includes:

[0063] In the case of color skipping, the longitudinal registration error is defined as the deviation in position between the printed mark of the current printing unit and the printed mark of the previous printing unit. The registration error model for a normal R2R printing system without color skipping is as follows:

[0064] ;

[0065] in, , , It is the change in tension between unit i and unit i+1. It is the registration error between unit i and unit i-1. It is the change in angular velocity of element i. It is the mesh length between unit i and unit i+1. It is the time taken to print the program between memory location i and memory location i+1. It is the radius of the printing roller. It is the elastic coefficient of the mesh fabric. It is the tension of the mesh in steady state. The steady-state value is the printing roller angular velocity. Printing unit number 1 does not have an registration controller, therefore... The unwinding section has a tension controller to maintain the tension of the mesh fed into unit 1 at a stable level. .

[0066] Considering the case of color-blocking printing, the registration error model under this condition can be divided into three parts: the upstream unit of the color-blocking unit, the color-blocking unit itself, and the downstream unit of the color-blocking unit. Assume... Unit color contrast, The registration error model for each printing unit before the unit is the same as the normal model; The unit was not involved in printing, so there is no registration error. The registration error model for each printing unit after the unit needs to be re-derived.

[0067] Furthermore, step S200 specifically includes:

[0068] like Figure 4 As shown, If the unit uses a contrasting color, then... The registration error of the element becomes the relationship between this element and... The deviation in the marking position between units changes the mesh length between that unit and the previous printing unit. , recorded as , Unit and The mesh tension between units is denoted as .

[0069] when At this time, the registration error was not affected by the color jump. The unit registration error model is as follows:

[0070] ;

[0071] when At that time, because the tension system between the two sections of the mesh fabric before and after the color-changing roller is combined into one section, it becomes... ,and The unit was not involved in printing, therefore at this time He Jun None of them exist.

[0072] when At that time, due to The unit does not exist. Transform into Printing unit and Registration error between printing units, at this time The cell registration error model is re-derived as follows:

[0073] ;

[0074] when At this time, except for the first printing unit downstream of the color-jumping roller, the mesh length between the remaining printing units remains unchanged and is not affected by the color-jumping. The derivation of the unit registration error model is as follows:

[0075] .

[0076] Furthermore, step S300 specifically includes:

[0077] Combining and rearranging the above formulas, and then performing a Laplace transform, we obtain:

[0078] ;

[0079] From the above relationship between registration error and mesh tension, the complete registration error-registration control model for the color-changing condition can be further obtained as follows:

[0080] ;

[0081] As shown in the above formulas, there is a coupling between mesh tension and registration error. Once the mesh tension expression for the skipped color segment changes, the mesh tension and corresponding registration error expression of subsequent printing units will also change. The above formulas construct a mathematical model of registration error under skipped color conditions in an R2R printing system. This model considers the variable mesh length between any two adjacent printing units. Furthermore, it is evident that the registration error of printing unit i is affected by the registration control of the current and upstream units, leading to complex coupling in the R2R printing system.

[0082] like Figure 5 As shown, the proposed model was verified through experiments. This was an open-loop experiment with 4-unit color skipping, with an initial offset of 3mm for printing unit 2 under equilibrium conditions. Registration error was measured using dual photoelectric sensors and a photoelectric encoder.

[0083] like Figure 6 , 7 As shown, the registration error of all downstream printing units is displayed, caused by an initial offset of 3mm in printing unit 2. The outputs of the established model and the actual model were compared with the same initial manual input on printing unit 2. The results show that, despite the interference, the model output curves for different printing units perfectly match the output curves of the actual system. This demonstrates that the proposed mathematical model provides sufficient accuracy to represent the characteristics of the industrial system.

[0084] This embodiment analyzes the changes in effective printing length between adjacent units caused by the selective discontinuation of printing units, derives the registration error equations for the first printing unit and subsequent units after color skipping, and further incorporates the coupling relationship between tension fluctuation, angular velocity adjustment and mesh tension into the model, thus deriving a complete system registration error model expression under color skipping conditions.

[0085] Furthermore, step S400 specifically includes:

[0086] The complete registration error model after color skipping consists of two parts, and correspondingly, the complete decoupling compensation after color skipping also consists of two parts. The compensation strategy before color skipping continues the original decoupling method of the normal model, and its stability has been verified. The decoupling compensation is as follows:

[0087] ;

[0088] The decoupling compensation after the color change needs to be redesigned based on the newly established model. First, the compensation formula is derived based on the established model and Lyapunov stability analysis theory. Then, a closed-loop control method based on selective decoupling is proposed.

[0089] Based on the registration error model for the color-changing condition proposed above, the following equation can be obtained:

[0090] ;

[0091] in It is a positive number representing the convergence speed of the registration error. Indicates the first The modeling error per printing unit. The R2R system operates near the equilibrium point, therefore the registration error is fully bounded. If there were no modeling error... , exist Under the given conditions, it should converge to zero. Taking the derivative, we get:

[0092] ;

[0093] in, It is also a positive number, and

[0094] ;

[0095] if make Then the above formula can be rewritten as

[0096] ;

[0097] The Lyapunov energy function is chosen as follows:

[0098] ;

[0099] Differentiating and simplifying the Lyapunov energy function, we get:

[0100] ;

[0101] Obviously, in the absence of modeling errors, when and hour, All are strictly negative numbers. According to Lyapunov's stability theorem, in Under the given conditions, the system is globally stable. However, in the presence of modeling errors, This is not always true. Therefore, based on the derivative of the Lyapunov energy function, the following equation is further derived:

[0102] ;

[0103] in ;

[0104] As can be seen from the above formula, when and , Decrease. Furthermore... .therefore Bounded. Based on the derivative of the Lyapunov energy function, the formula can also be rewritten as:

[0105] ;

[0106] Integrating it, we get:

[0107] ;

[0108] The above formula can be further rewritten as:

[0109] ;

[0110] Therefore, it can be proven It is bounded and related to the modeling error. Related. Due to It is uniform and continuous, which means It can converge to a certain range. In summary, if there is no modeling error... , It is stable and asymptotically converges to zero. make It is always zero. However, there is a modeling error. In this case, It is also stable and can converge to a certain range.

[0111] Assumption It is compensation, Replace with and make the above In the expression We can obtain:

[0112] ;

[0113] By performing a Laplace transform on it and combining it with the expression for color-blocking registration error, we can obtain:

[0114] ;

[0115] In the above expression Solving for the given information yields:

[0116] ;

[0117] This expression can be further written as:

[0118] ;

[0119] in

[0120] ;

[0121] Upstream registration control includes closed-loop control of the current printing unit (PD control in this embodiment) and decoupling compensation for upstream registration control, i.e.

[0122] ;

[0123] Substitute the aforementioned upstream registration control quantity into the compensation quantity. The complete compensation expression for the registration error model of the R2R printing system after color skipping is obtained from the expression:

[0124] ;

[0125] in Clearly, this compensation makes Thus This means that compensation can ensure the convergence of registration errors.

[0126] like Figure 2 As shown, in the model-based selective decoupling control scheme, PD control is used to reduce the uncoupled registration error between printing units, while model-based selective decoupling is used to compensate for the influence of upstream unit registration control coupling. PD control and model-based selective decoupling compensation together constitute a complete model-based selective decoupling control algorithm.

[0127] like Figure 8 As shown, the model-based selective decoupling control algorithm is applied to an industrial example. With an initial disturbance of 3mm to unit 2, the model-based selective decoupling control method can maintain the registration error of subsequent printing units within ±0.07mm, without significant fluctuations. After stabilization, the registration error of units 2 and 3 controlled by the model-based selective decoupling control method remains within ±5×10⁻⁶ mm. -5 Within the range of m.

[0128] like Figure 9 As shown, the maximum absolute value of the overlay error for elements 5-7 is less than 15 × 10⁻⁶. -5 m, with a maximum value of only 11 × 10 - 5 The results show that the proposed model-based selective decoupling control algorithm can effectively remove the coupling of the color-skipping model and eliminate the registration error, while keeping the registration error within a high accuracy range, namely ±7×10⁻⁵m.

[0129] like Figure 3 As shown, this embodiment provides a roll-to-roll printing machine, including:

[0130] Unwinding section, rewinding section, feeding section, unloading section, and multi-color printing section.

[0131] The unwinding section releases the roll material, and the tension control system maintains the stability of the roll material tension.

[0132] After being pulled and tensioned by the feeding section, the roll material smoothly enters the multi-color printing section;

[0133] After entering the multi-color printing section, the roll material is pressed against the roller under the action of the pressure roller to transfer the pattern, and the patterns are stacked one after another to form multi-color printing;

[0134] The discharge section performs post-processing and pre-rewinding preparations, including final drying of the ink, material cooling to stabilize the ink layer, and finally stabilizing the conveying tension.

[0135] The take-up section rewinds the finished product into a roll, ensuring that the roll is tight, neat, and free of internal wrinkles or indentations, thus completing the roll winding process.

[0136] Each section is connected by a constant roll tension as the main line. The feed section and the output section serve as tension buffer hubs to absorb fluctuations and ensure that the roll material enters and leaves the multi-color printing section smoothly. All printing rollers are controlled by a synchronous drive system to ensure consistent linear speed. The registration error system reads the printing marks and links each printing unit to ensure registration accuracy. The entire process is coordinated by a central controller to achieve efficient collaboration among all modules.

[0137] This embodiment also provides a computer program product, including: a computer program used to implement the longitudinal registration error modeling and decoupling control method of the roll-to-roll printing system under color skipping conditions.

[0138] This invention proposes a method for modeling and decoupling control of longitudinal registration error in roll-to-roll printing systems under color-skipping conditions, a roll-to-roll printing press, and a computer program product. This method addresses the selective shutdown of printing units in roll-to-roll printing systems, a previously unexplored area where a specific model accurately describes this process is lacking. This invention achieves high-precision modeling under color-skipping conditions and remains applicable to varying feed lengths, linear speeds, and roll substrate tensions. It is not only simple and efficient to implement, but also offers superior control, making it highly suitable for widespread use in roll-to-roll printing systems with selective printing unit shutdown. Furthermore, it provides a more effective dynamic model foundation for future development of other advanced control strategies for roll-to-roll printing systems. The modeling and control method for selective shutdown of printing units in roll-to-roll printing systems exhibits excellent industrial performance and is applicable to variations in tension range and feed lengths across different printing equipment models. This modeling method can be applied to registration error modeling under color-skipping conditions in various types of roll-to-roll printing equipment. Furthermore, a feedforward compensation mechanism was designed to effectively offset upstream deterministic disturbances, and combined with PD feedback to suppress residual errors, providing key technical support for improving the registration accuracy and product yield of large-scale continuous printing.

[0139] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for modeling and decoupling control of longitudinal registration error in a roll-to-roll printing system under color skipping conditions, characterized in that, include: Based on the roll material transport characteristics and printing unit dynamic parameters under the color skipping condition of roll-to-roll printing press, a registration error model based on variable mesh length is established. The changes in effective printing length between adjacent printing units caused by selective disabling are analyzed, and the registration error model of the first printing unit and subsequent units after color skipping is derived. The coupling relationship between tension fluctuation, angular velocity adjustment and elastic deformation of the mesh is incorporated into the registration error model to construct a registration error model for the complete system under the color-changing condition. A selective decoupling compensator is constructed based on the registration error model of the complete system and combined with Lyapunov stability theory to compensate for the coupling disturbance caused by color jumping. The selective decoupling compensator, combined with pre-color-skipping registration control, enables roll-to-roll color-skipping printing registration accuracy control.

2. The method for modeling and decoupling control of longitudinal registration error in a roll-to-roll printing system under color skipping conditions as described in claim 1, characterized in that, Establishing a registration error model based on variable mesh length includes: In the case of color skipping, the longitudinal registration error is defined as the positional deviation between the printed mark of the current printing unit and the printed mark of the previous printing unit. Based on the registration error model under normal working conditions, it is divided into three parts: upstream unit of the color-jumping unit, color-jumping unit, and downstream unit of the color-jumping unit, and modeled separately. For the upstream unit of the color-jumping unit, the registration error model is the same as the model when no color-jumping occurs; for the color-jumping unit, there is no registration error; for the downstream unit of the color-jumping unit, a corresponding registration error model is constructed.

3. The method for modeling and decoupling control of longitudinal registration error in a roll-to-roll printing system under color skipping conditions as described in claim 2, characterized in that, The analysis of the changes in effective print length between adjacent printing units caused by selective shutdown includes: After determining the position of the color-jumping unit, the registration error of the first printing unit downstream of the color-jumping unit becomes the deviation of the marked position between this unit and the unit preceding the color-jumping unit; The mesh length between the color-blocking unit and the downstream unit is merged into a new length; The mesh tension between the first printing unit downstream of the color-blocking unit and the unit preceding the color-blocking unit is redefined; Based on the variation in mesh length, the downstream unit alignment error model is derived segment by segment.

4. The method according to claim 3, wherein the method is characterized in that, The coupling relationship between tension fluctuation, angular velocity adjustment, and elastic deformation of the mesh is incorporated into the registration error model, including: The segmented equations for the registration error under the color-changing condition are combined and organized. The relationship between registration error and mesh tension in the frequency domain is obtained through Laplace transform; Construct the registration error-registration control model expression for the complete system under the color-changing condition; Clarify the coupling relationship between the registration error and the registration control of the current and upstream units.

5. The method according to claim 4, wherein the method is characterized in that, A selective decoupling compensator is constructed based on the registration error model of the complete system and combined with Lyapunov stability theory, including: Based on the registration error model of color-changing working conditions, the compensation conditions for system stability are derived. The stability and convergence of the system were analyzed using the Lyapunov energy function. Construct a feedforward compensation mechanism to ensure that the coupling effect of upstream unit angular velocity adjustment on downstream unit is zero; The frequency domain expression of the compensation amount is derived to achieve deterministic disturbance cancellation.

6. The method of claim 5, wherein the method is a method for modeling and decoupling the longitudinal register error of the roll-to-roll printing system in the skip-color mode of operation. The selective decoupling compensator, combined with pre-registration control for color-skipping printing, enables roll-to-roll color-skipping printing registration accuracy control, including: The upstream alignment control quantity is divided into the upstream alignment control output of the current unit and the decoupling compensation quantity for the upstream alignment control. The decoupling method for units before color transition continues the normal model; After color-changing, the decoupling compensation formula of the unit is redesigned based on the new model; Upstream registration control is used to reduce uncoupled registration errors, while selective decoupling compensation is used to counteract the effects of upstream coupling.

7. A roll-to-roll printer characterized in that, For implementing the longitudinal registration error modeling and decoupling control method of the roll-to-roll printing system as described in any one of claims 1-6 under color skipping conditions, the roll-to-roll printing machine includes: an unwinding section, a rewinding section, a feeding section, an output section, and a multi-color printing section. The unwinding section releases the roll material, and the tension control system maintains the stability of the roll material tension. After being pulled and tensioned by the feeding section, the roll material smoothly enters the multi-color printing section; After entering the multi-color printing section, the roll material is pressed against the roller under the action of the pressure roller to transfer the pattern, and the patterns are stacked one after another to form multi-color printing; The discharge section performs post-processing and pre-rewinding preparations, including final drying of the ink, material cooling to stabilize the ink layer, and finally stabilizing the conveying tension. The take-up section rewinds the finished product into a roll, ensuring that the roll is tight, neat, and free of internal wrinkles or indentations, thus completing the roll winding process. Each section is connected by a constant roll tension as the main line. The feed section and the output section serve as tension buffer hubs to absorb fluctuations and ensure that the roll material enters and leaves the multi-color printing section smoothly. All printing rollers are controlled by a synchronous drive system to ensure consistent linear speed. The registration error system reads the printing marks and links each printing unit to ensure registration accuracy. The entire process is coordinated by a central controller to achieve efficient collaboration among all modules.

8. A computer program product comprising a computer program, characterized in that, The computer program is used to implement the longitudinal registration error modeling and decoupling control method of the roll-to-roll printing system as described in any one of claims 1-6 under color skipping conditions.

Images